Thermo Scientific 3906 Operating Manual page 49

Thermo Scientific
The dehumidify switch is used with the optional heatless dryer P/N 1900139 to provide
dehumidification. The heatless dryer injects dry air into the environmental chamber as
needed, to maintain humidity levels. When controlling humidity, the dehumidification
switch should be in the ON position for most applications. The dehumidification light will
cycle on and off as the humidity controller toggles between humidify and dehumidify.
Time switch light modules
Figure 8-4
The time switch controls the LED light tubes of the light modules.
Humidity Alarm
Humidity
Controller
Indicator lights
Indicator Lights and Controls
Figure 8-5
Heat Indicator (Figure 8-5)
The Heat Indicator illuminates when the heater activates.
Cool Indicator (Figure 8-5)
The Cool Indicator illuminates when the refrigeration system activates.
Overtemp Safety Control, Indicator Light & Audible Alarm (Figure 8-5)
The overtemp safety thermostat should be set slightly above the operating temperature of
the environmental chamber. In the event of an overtemp condition, the overtemp safety
thermostat:
Activate the audible alarm and the overtemp indicator light.

Temperature Controller
Cool Indicator
Heat Indicator
Handling and Control |
Chapter 8
Overtemp &
Undertemp
Controls
Model 3900 Series | 8-3